<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        button {
            margin-top: 600px;
            margin-left: 300px;
        }

        iframe {
            margin-top: 5000px;
            margin-left: 5000px;
        }
    </style>
</head>
<body>

    <button>click me in child</button>
    <iframe src="http://localhost:3001/fixtures/regression/gh-7557/pages/nested-frame.html"></iframe>

    <script>
        document.querySelector('button').addEventListener('click', function (e) {
            e.target.style.backgroundColor = 'blue';

            window.clickedInChild = true;
        });
    </script>
</body>
</html>
